Sm0.5Sr0.5CoO3-δsurface modification of La0.6Sr0.4Co0.2Fe0.8O3-δ-Ce0.9Gd0.12-δComposite Oxygen Electrodes for Solid Oxide Electrochemical Cells

Matthew Y. Lu, Tianrang Yang, Roberto Scipioni, Yvonne A. Chart, Alexander Furlong, Scott A. Barnett

Research output: Contribution to journalArticlepeer-review

Abstract

La0.6Sr0.4Co0.2Fe0.8O3-δ-Ce0.9Gd0.1O2-δ (LSCF-GDC) composite oxygen electrodes have been widely used in intermediate temperature (<700 °C) solid oxide cells, with composite usually providing better electrochemical performance than single-phase LSCF. However, LSCF-based electrodes are often observed to degrade over time due to Sr segregation. Here we present an impedance spectroscopy study comparing the degradation behaviors of LSCF-GDC and Sm0.5Sr0.5CoO3-δ (SSC) infiltrated LSCF-GDC electrodes. The LSCF-GDC polarization resistance increases by ∼5 times over ∼1000 h at 650 °C. In contrast, the SSC-infiltrated electrode shows similar initial polarization resistance but much more stable performance. The impedance modeling results show that the improved stability is associated with the low frequency oxygen dissociative adsorption/desorption process. The results suggest that this adsorption/desorption process slows due to increased Sr segregation on LSCF over time, and that SSC does not degrade significantly due to Sr surface segregation.

Original languageEnglish (US)
Article number164504
JournalJournal of the Electrochemical Society
Volume167
Issue number16
DOIs
StatePublished - Dec 2020

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Renewable Energy, Sustainability and the Environment
  • Surfaces, Coatings and Films
  • Electrochemistry
  • Materials Chemistry

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